I’ve just tested this out. I evolved an appropriately named Eevee and found it to be correct with one test for each type. I then evolved 15 unnamed Eevees, which all turned into one of the 3 Generation 1 types.

Lesson: Assuming the trick only works once like the Generation 1 renaming trick, you should be careful about what how much IV rating your Eevee has before you make it an Espeon – because it might be hard to get another Espeon!